Breeding for fertilizer-efficient rice is paramount. The succeeding research aimed to study the genetic makeup and selection procedure for tolerant rice genotypes in minimum fertilizer. The genetic material comprised 106 F₅ rice lines and five check genotypes grown under optimum and minimum fertilizer conditions. The experiment layout was in an augmented design with five replications. The results indicated genotype-by-environment interactions significantly (p < 0.01) affected rice yield-related traits, specifically productivity. The identified rice lines totaled 26 through multi-trait genotype-ideotype distance index (MGIDI) analysis using 25% selection intensity. The heritability value in the optimal environment (0.725) was higher than in the minimum environment (0.628). Similarly, values for genetic advance (GA) and genetic advance as a percentage of the mean (GAM) in the optimal environment (1.160% and 18.680%) were higher than those in the minimum environment (0.659% and 13.158%). The geometric mean productivity (GMP), harmonic mean (HM), mean productivity (MP), and stress tolerance index (STI) exhibited a significant positive correlation with the average yield under optimum conditions (Yp) and minimum conditions (Ys). However, the stress susceptibility index (SSI) and tolerance index (TOL) showed a negative correlation with Ys, indicating selection based on the tolerance index identified the best lines, G27 and G66.

Keywords: Rice (O. sativa L.), F₅ populations, minimum fertilizer, selection, heritability, genetic gain, tolerance indices, yield-related traits

Key findings: The study highlighted the use of the MGIDI method and tolerance indices (TOL, SSI, STI, MP, HM, and GMP) in identifying promising rice (O. sativa L.) genotypes better suited for low-fertilization conditions. These insights serve as a valuable resource for optimizing fertilizer efficiency to enhance sustainable rice production.

The wheat advanced lines of the F5 generation, obtained through interspecific hybridization (T. durum × T. aestivum), incurred studies for salt tolerance in terms of morphophysiological traits and grain yield under normal and saline soil conditions. The results revealed that salt caused a significant decrease in the photosynthetic pigments, photosystem II activity, and relative water content in the leaves of advanced wheat lines. Overall, the saline stress conditions considerably affected the photosynthetic pigments in most of the advanced lines, while in some genotypes, it was relatively less. Thus, the chlorophyll (a+b), carotenoids, photosystem II activity, and relative water content were more pronounced in the hybrids Leyaqatli-80 × Mirbashir-128, Tale-38 × Kyrmyzy gul-1, Gobustan × Sheki-1, and Mirbashir-50 × Shiraslan-23 than in other hybrids. These hybrids showed greater salt tolerance. On grain yield losses in saline soil, the hybrids Murov × Daghdash, Tale-38 × Kyrmyzy gul-1, Gobustan × Sheki-1, Barakatli-95 × Vugar, Mirbashir-50 × Shiraslan-23, Gobustan × Barakatli-95, Garabagh × Mirbashir-128, and Garabagh × Shark displayed higher resistance. This resistance was for ear weight, the number of grains, and grain weight. In the future, growing these advanced wheat lines under wider saline areas as salt-tolerant cultivars can be successful.

Keywords: Wheat interspecific (T. durum × T. aestivum) advanced lines, saline stress conditions, heterosis, dominance, morphophysiological traits, spike traits, productivity

Key findings: The study identified the promising wheat interspecific (T. durum × T. aestivum) advanced lines for heterotic and dominance effects over better parents for yield-related traits that can help in developing high-yielding wheat genotypes.

The following research comprised the discussion on the spread of the maize dwarf mosaic virus (MDMV), virus transmission, and scientifically based measures to combat the virus. The MDMV monitoring centered on the spread, diagnosis, and impact of the virus on morphophysiological traits and productivity of different maize cultivars. Over the past four years of research, the MDMV infection in corn samples was 44.7% (2020), 35.9% (2021), 27.0% (2022), and 23.0% (2023). The MDMV level of infection declined every year due to comprehensive measures to combat MDMV. In identifying reserve plants and vectors (aphids) of the virus, the main provision aimed at the use of various methods in combating the MDMV. The results revealed Sorghum halepense Pers. was the chief reservoir of MDMV. The complex control measures include selection of cultivars and hybrids resistant to MDMV. Based on the results, determining the corn cultivars emerged from their resistance to the MDMV. The hybrids Legend F1 from France, DKS 4141 F1 from Turkey, and Phenomenon F1 from Switzerland were notable with an average degree of MDMV infection. The degrees of infection were highest in the maize cultivar Mazza from Uzbekistan and the hybrid Megaton F1 from France, which proved not resistant.

Keywords: Maize dwarf mosaic virus (MDMV), maize cultivars and hybrids, virus host and transmission, Sorghum halepense Pers., vectors, morphophysiological traits, productivity

Key findings: For the maize dwarf mosaic virus (MDMV), the Sorghum halepense Pers. was apparently the main reservoir. In complex control measures, the corn cultivars’ identification occurred from their resistance to MDMV.

Cassava tuberous roots are rich in starch but deficient in micronutrients such as provitamin A. The cassava cultivar Carvita-25 is a yellow variant of a white-fleshed cassava genotype (Adira-4) obtained through friable embryogenic callus. The following study aimed to ascertain substantial disparities in metabolite profiles and gene transcripts associated with carotenoid-related characteristics. Genotype Carvita-25 contains β-carotene and its derivative apocarotenoid, responsible for the yellow coloration of the tubers. The metabolite profile exhibited discrepancies in metabolite composition between the cultivars Adira-4 and Carvita-25. Genotype Adira-4 contains the highest levels of amino acid compounds, peptides, and their derivatives, while genotype Carvita-25 contains more amine-type compounds. Differential transcription levels were notable among the genes responsible for carotenoid biosynthesis, Manes.02G081700.1 (PSY1). An enhanced transcription level of PSY1 was evident in Carvita-25 compared with Adira-4, while the lower transcription level of PSY2 resulted in Carvita-25 compared with Adira-4. The GO (gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses revealed the upregulation of 2,000 genes and downregulation of 1,772 genes in Carvita-25 compared with Adira-4. These comprise cytochrome P450 (CYP82D47), and bHLH family transcription factors were the candidate regulators of carotenoid-related genes in root tubers. This information can be further applicable to developing strategies for improving the quality of cassava plants rich in carotenoid compounds.

Keywords: Cassava genotypes, apocarotenoids, metabolites, phytoene synthase, transcriptome, yellow-fleshed cassava

Key findings: Carvita-25, a mutant cassava, has appeared to contain beta carotene and apocarotenoid metabolites with provitamin-A functions. The discrepancies in phytoene synthase genes and PSY1 and cytochrome 450 (CYP82D47) have been the identified primary factors contributing to variances in the carotenoid profile of Carvita-25 from Adira-4.

Cacao (Theobroma cacao L.) is an important export crop, requiring high-quality beans with sustainable production to meet market demands. For genetic enhancement, controlled hybridization provides a pathway to improving bean quality and increasing genetic variation in cacao. This study evaluated phenotypic variation in 16 quantitative traits of F1 progeny derived from four cross combinations and performed molecular characterization using 11 polymorphic markers. Data collection progressed in 2019–2021. Notably, the F1 hybrid TSH858 x DR1 emerged as promising by showing higher average pod weight and favorable bean counts per 100 g, aligning with AA/A quality grades. The F1 hybrid 5-1 (2) showcased the highest single dried bean weight and lowest pod index, indicating large bean sizes. Molecular characterization revealed the highest observed (0.64) and expected (0.56) heterozygosity, confirming the origins of hybrids. The average polymorphism information content (PIC) was 0.50, suitable for genetic studies. Distinct genetic relationships among the F1 progenies suggested that bean yield and quality variations stem from genetic variation. The results highlighted that strategic hybridization played a vital role in boosting genetic diversity and bean quality as key goals in cacao breeding programs.

Keywords: Cacao (T. cacao L.) breeding, bean quality, controlled hybridization, genetic variation, molecular characterization, heterozygosity, genetic relationship

Key findings: This study integrates morphological, agronomic, and molecular data to comprehensively evaluate the cacao (T. cacao L.) F1 hybrids. The combined use of phenotypic traits and molecular characterization strengthens the selection strategies for breeding. Emphasis on pod index, yield traits, and quality standards aligns the findings with practical breeding goals and industry needs.

Soybean (Glycine max L.) genotypes that combine high yield and pod-shatter resistance are essential for improving productivity, particularly under tropical conditions. The following study evaluated the agronomic performance and pod-shattering resistance of 16 soybean genotypes, including 14 elite breeding lines and two check cultivars, across two locations in East Java, Indonesia. Significant genotype-by-environment interactions (p ≤ 0.01) emerged for most agronomic traits, except plant height, empty pods, and seed yield. Seed yield ranged from 2.50 to 3.46 t/ha, with an overall average of 3.03 t/ha, and had a positive correlation with the number of nodes and filled pods. Four genotypes (G1, G4, G11, and G15) were highly resistant to pod shattering. Selection based on multiple traits using the GT biplot successfully identified six soybean genotypes (G1, G2, G4, G5, G8, and G15) that exhibited the best performance for filled pods, seed yield, and resistance to pod shattering. These findings demonstrate the effectiveness of multi-trait selection using the GT biplot and provide promising candidate lines for developing high-yielding, pod-shattering-resistant soybean cultivars adapted to tropical environments.

Keywords: Soybean (G. max L.), yield-related traits, pod-shattering resistance, genotype-environment interaction, correlation, multiple traits

Key findings: In soybeans (G. max L.), the seed yield proved considerably and positively correlated with the number of nodes and filled pods. The high-yielding soybean genotypes with pod-shattering resistance and desirable agronomic traits identified through genotype-by-trait biplot analysis could serve as promising genetic resources for the development of new cultivars in breeding programs.

Rice (Oryza sativa L.) landraces represent a valuable genetic resource that can play an important role in sustainable crop production and biodiversity conservation for the future. However, the cultivation and genetic diversity of these landraces in the Mekong Delta have been unacceptable due to widespread adoption of high-yielding rice cultivars and intensive farming practices, leading to environmental degradation and biodiversity losses. The following study evaluated the morphological and grain traits of 65 rice landraces from the Mekong Delta, conserved in the Gene Bank of Can Tho University, Vietnam. The landraces underwent cultivation in field conditions and assessment based on the evaluation system of the International Rice Research Institute (IRRI), Philippines. Grain quality analysis focused on grain size and shape. The genome-wide association study was successful in identifying the genomic regions linked to the morpho-agronomic traits in landraces of the Mekong Delta using single nucleotide polymorphisms (SNPs). Correlation analysis helped link the genetic characteristics with 11 traits, and candidate genes associated with 681 significant SNPs attained identification using the Rice SNP-Seek Database. The findings provided valuable insights into the genetic and phenotypic diversity of rice landraces for further improvement and germplasm conservation in the Mekong Delta, Vietnam.

Keywords: Rice (O. sativa L.), landraces, genetic variations, biodiversity, agronomic traits, candidate genes, GWAS

Key findings: This study identified 46 candidate SNPs within 32 genes associated with 11 agronomic traits in 65 rice (O. sativa L.) landraces. Plant height and brown rice shape are the key traits for breeding, with new candidate SNPs linked to them.

The study aimed at examining the impacts of various irrigation systems on passion fruit (Passiflora edulis Sims) seedlings in addition to foliar treatments through N-P-K fertilizer (20-20-20). It was carried out in the greenhouse of the green university of Al-Qasim at Babil in Iraq between 15 September 2023 and 15 March 2024. Seedlings were planted using plastic bags with the capacity of 3 kg. The study was done under experimental design of randomized complete block design with two factors. The former factor comprised two irrigation systems, which included sprinkler and drip irrigation. The second reason was that of the foliar application of N-P-K fertilizer using three levels (0, 2, and 4 g L-1). The findings indicated that there were vast distinctions in the vegetative growth characteristics under investigation such as plant height, diameter of the stem, amount of branches, amount of leaves, and content of chlorophyll. The highest values were realized with the sprinkler irrigation system in addition to a compound fertilizer (N-P-K) of a concentration of 4g/L/L when compared to the drip irrigation system and the control treatment.

Keywords: Passion fruit (P. edulis Sims), irrigation methods, N-P-K fertilizer, foliar fertilization, vegetative growth, chlorophyll content

Key findings: Passion fruit (P. edulis Sims) showed the best vegetative growth values when it was combined with the sprinkler irrigation system and NPK fertilizer. Conversely, the treatment group that applied drip irrigation and applied no supplementary fertilizer, known as control treatment, did not have as many variations in the vegetative growth as compared to the other treatment groups.

Various processes can boost growth traits and the nutritional value of fruits. One such technique is the application of chelating substances for enhancing crop growth and productivity. The following study aimed to determine the effect of humic acid and chelated iron on the growth and nutritional content of apple (Malus domestica L.) cv. Sharabi, carried out in 2022 at the University of Kufa, Iraq, The experimental layout was in a randomized complete block design with three replications. The experiment included nine fertilizer combinations of the humic acid and chelated iron in different ratios. Results showed the fertilizer combination of humic acid (5 ml L^-1) + chelated iron (30 mg L^-1) was superior in the apple seedling height, number of branches, number of leaves, leaf area, dry weight of shoots, carbohydrate content, and nitrogen content, with an increased average values (39.33 cm, 7.84 branches seedling^-1, 295.07 leaves seedling^-1, 33.01 cm², 43.46 g, 8.81 mg g^-1, and 2.42%, respectively). The fertilizer combination of humic acid (5 ml L^-1) + chelated iron (0 mg L^-1) excelled in the fresh weight of shoots and the chlorophyll content (99.18 g and 36.10 mg g^-1, respectively). For phosphorus content, the combination of humic acid (2.5 ml L^-1) and chelated iron (15 mg L^-1) was leading with an average of 0.57%, while for potassium content, the combination of excelled humic acid (5 ml L^-1) and chelated iron (15 mg L^-1) showed the highest average (3.90%) in the apple cultivar Sharabi.

Keywords: Apple (M. domestica L.), humic acid, chelated iron, growth and yield traits, nutritional content

Key findings: In apple (M. domestica L.), the fertilizer combination of humic acid (5 ml L^-1) + chelated iron (30 mg L^-1) proved superior in most traits, such as seedling height, the number of branches and leaves, leaf area, dry weight of shoots, and carbohydrate and nitrogen contents.

Guava (Psidium guajava L.) is a nutraceutical commercial fruit crop of the subtropics. Twenty-one accessions of round or Gola cultivars were collected from Punjab and Khyber Pakhtunkhwa (KPK) provinces having diverse climatic conditions. This indigenous germplasm bore investigation for 17 physicochemical fruit traits. The assessment sought to estimate variability and population structure. Accessions collected from Punjab had greater genotypic diversity and a wider genetic base than accessions from KPK. Several accessions proved superior for economically important consumer-related fruit traits, including fruit weight (FW), fruit size (FS), total soluble solids (TSS), ratio of TSS to titratable acidity (TA), and total sugars (TS). Most physical traits displayed positive correlations, whereas chemical traits had a negative correlation. Accessions with larger fruit size and fewer seeds indicated an association with lower TSS. Prevailing low temperatures in both areas enhanced fruit size and decreased total sugars. The principal component analysis (PCA) depicted higher loadings of FW, seed cavity weight (SCW), number of seeds (NS), and TS and grouping of most accessions of a locality in one cluster. The selected accessions, as vegetatively propagated, could serve as candidate varieties used for genetic association studies and as parental lines for the development of hybrids with better horticultural traits.

Keywords: Guava germplasm, biodiversity, fruit quality, principal component analysis, breeding

Key findings: The Round accessions, G₁, G₅, G₁₃, and G₁₈, are suitable candidates for better fruit weight and size. Meanwhile, the apple guava G₉ could be a strong parental candidate for reduced number of seeds, higher TSS, TSS:TA, and dark red skin—a consumer-preferred trait.